derraileur catching; what's wrong?

deandean

I am hoping someone has fixed this problem before. I am stumped.

27sp mtb, when on the granny ring on the front, and any cog on the back, the derailleur seems to sieze and pulls up with the chain, only when under pressure.

Chain, casette, derIlleur cogs are 1 yr old prob with 1000km.
I have adjusted the cable several times, can't get rid of the problem.

Any advice appreciated.
Dean.

victorcarrera

The chain might be too long or worn.
If the top pulley wheel is touching the rear cogs change the b adjustment.

morana

Could be a slightly bent tooth on the granny ring or something snagging it up front.

From what you said I assume the derailleur is going forward towards the chainrings so I guess the chain is not coming off the granny ring properly

bcmf

Sounds a bit like chain suck.
A good clean of chainrings, cassette, jockey wheels and chain.If you feel confident enough remove the jockey wheels and take off the washers ( they will pop off themselves) and clean inside the washer and inside the jockey wheel itself.
If that doesnt work then your granny ring maybe worn.

el Bastardo

+1

I had a problem like this on a practically new bike. I replaced the entire drive train, which was completely unnecessary. I now know, after learning the hard way, that it was just a worn, elongated chain that was causing it. Consider buying a chain gauge or at least measure your chain; My chains never last much beyond 1000 Km.

victorcarrera wrote: »

The chain might be too long or worn.
If the top pulley wheel is touching the rear cogs change the b adjustment.

deandean

Sorted!

It was the 'B' adjustment, which I reckon I never looked at ever. I added 1.5 turns so the derailleur is a little further from the cogs, and happy days.

Thanks all, 'specially victorcarrera.